Work-holding assembly

ABSTRACT

In a work-holding assembly wherein a workpiece is supported while fed to a working location, a main work-holding means includes a pair of main jaws which hold the workpiece, and an auxiliary work-holding means includes a pair of auxiliary jaws which also engage the work. A connecting means in the form of a pair of elongated bars interconnects the auxiliary jaws with the main jaws. With this arrangement, while the main jaws are in the region where working of the workpiece takes place, the auxiliary jaws are also located in this region so as to support even a relatively short workpiece in the direct vicinity of the region where it is worked upon by devices such as, for example, wedgerolls.

nitenl @tates Patent Hlladlhy [4 1 Fella, 22, T1972 [54] WVUIRM-HQMLDIING ASWEMEELY 3,011,464 12/1961 Danly et a1 ..72/405 Inventor: Vida, Hlfldky, Brno, Czechoslovakia 614,1 1 1 1 1/1898 Johnston .72/252 [73] Assignee: /yzlltnmny ustav tvarecich strain a Primary Examiner-Lowell A. Larson technologie tvareni, Brno, Czechoslovakia Attorney-Richard Low [22] Filed: Apr. 7, 11969 ABSTRACT 21 A 1. No.: 8113 8'72 1 pp In a work-holding assembly wherein a workpiece is supported while fed to a working location, a main work-holding means U-S. @l includes a pair of mainjaws which the workpiece and an [51] Hint. Cl .Bllh 9/00 auxiliary work holding means includes a pair f auxmary jaws [58] them all Search ..72 102, 108, 109, 405, 420, which also engage the work A connecting means in the form 72/422 1016' 11; 226/115 162; 269/153 of a pair of elongated bars interconnects the auxiliary jaws with the main jaws. With this arrangement, while the main [56] Refemmas jaws are in the region where working of the workpiece takes UNITED STATES PATENTS place, the auxiliary jaws are also located in this region so asto support even a relatively short workpiece m the direct vicinity TBbbEttS of the reginn where it is worked upon devices uch as fur 635,215 10/ 1899 White ..72/422 l wedge-rolls, 1,916,608 7/1933 Ehinger ...72/405 2,842,990 7/1958 Hubl ..72/ 109 35 Clairns, 3 Drawing Figures WOiRllfi-lI-IOLDING ASSEMBLY BACKGROUND OF THE INVENTION The present invention relates to work-holding devices. In particular, it relates to devices for holding workpieces which are rotated while they are worked, such as workpieces acted upon by wedge-rolls which serve to give a rotary workpiece that initially is of a uniform cross section a configuration of predetermined shape different from the initial uniform cross section of the work.

With machines of the latter type, as disclosed, for example, in U.S. Pat. No. 3,208,257, there are a pair of wedge-rolls which rotate in the same direction but have their adjacent peripheral portions, which engage the work, moving in opposite directions so that the work is rotated while the wedgerolls will impart to the work a predetermined configuration in accordance with the shape of the wedge'rolls.

In the case of these machines, the work is axially introduced into the region where the working between the wedge-rolls takes place. A suitable work-feeding device is used for this purpose.

Thus, the rod which forms the workpiece is fed into the machine while being gripped by jaws of the feeding device which may be actuated, for example, by compressed air. The feeding of the rod takes place during a time when actual rolling is not taking place so that at this time the rod can be freely introduced into the space between the wedge-rolls. In asmuch as the rod is guided by a guide sleeve situated as close to the edges of the wedge-rolls as possible, considered in the axial direction, it is unavoidable that the work-feeding device will be located outwardly beyond this guide sleeve at a distance determined by the length of the feeding stroke provided for the rod and by the width of the work-feeding components.

As a result, there comes a time when an end of the rod which is worked is not and cannot be held any longer by the work-holding jaws of the work-feeding device. At this time the workpiece can only be pushed into the working region by axial pressure of the next rod, so that a residual relatively short end of a given rod will only be guided by the guide sleeve. It may, therefore, occur that the rod does not enter the recess formed in a stop member which limits the feeding stroke and that the proper location of the work must be carried out manually under these conditions. This is a serious disadvantage in connection with the operation of such machines.

Furthermore, during actual working of the workpiece it may happen that, due to the fact that the rod is not perfectly straight, it is not accurately located in the recess of the stop member.

SUMMARY OF THE INVENTION It is, accordingly, a primary object of the present invention to provide a work-holding assembly which will avoid the referred-to drawbacks.

More particularly, it is an object of this invention to provide a work-holding assembly which will reliably hold and support even relatively short residual workpieces at the end of a bar or rod when such a residual workpiece is engaged by the leading end of the next rod which constitutes the succeeding workpiece.

Another object of the invention is to provide a construction which can easily be adjusted to workpieces of different lengths.

A further object of my invention is to provide a construction which is relatively simple and inexpensive to manufacture and assemble and which in addition can readily be added to existing known structures without any great expense or radical changes in the conventional work-holding structure.

In accordance with the invention, the work-holding assembly includes a main work-holding means formed by a pair of main work-holding jaws movable toward and away from the workpiece, and an auxiliary work-holding means formed by a pair of auxiliary jaws movable toward and away from the workpiece. A connecting means connects the auxiliary workholding means to the main work-holding means, and includes a pair of elongated bars connected on the one hand to the auxiliary jaws and on the other hand to the main jaws so that in this way the auxiliary jaws will move together with the main jaws into and out of engagement with the work. Preferably, an adjusting means is provided for adjusting the location of the connection between the auxiliary jaws and the bars which form the connecting means so that the distance between the auxiliary and main work-holding means can be adjusted.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. l is a schematic side elevation of a work-holding assembly according to the invention, shown at an instant when a new rod holds a relatively short residual end portion of a workpiece in the working region, the assembly being shown in connection with wedge-rolls which will shape the work in a well-known manner;

FIG. 2 is a top plan view of the structure of FIG. ll, shown without the wedge-rolls to more clearly illustrate the structure of the invention;

FIG. 3 is a transverse elevation of the structure as it appears when viewed from the left of FIGS. 11 and 2, showing the main and auxiliary jaws.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawing in greater detail now, a workpiece l is illustrated as an elongated rod which is of uniform circular cross section along its entire length. A known feeding unit 2 serves to urge the rods ll axially toward the left, as viewed in FIGS. 1 and 2, along a given working stroke, with several rods ll following coaxially one after the other. The workpiece l which is in the vicinity of where the working takes place passes through a guide sleeve 3 located in and carried by a suitable holder 13, so that the guide sleeve 3 will support the work for rotary movement about its axis while the work extends through the space between the wedge-rolls l and 5 which are provided with work-shaping components 6 which are well known by themselves. The leading end of the workpiece is received in a recess formed in the head '7 ofa stop member ti.

The work-feeding structure includes a main work-holding means 9 which may be pneumatically actuated and is provided with a pair of main work-holding or clamping jaws It). The pneumatic structure for actuating the main work-holding means 9 is not illustrated since it is well known. This structure operates in a known way to displace the main jaws ll) toward each other into engagement with the workpiece and away from each other out of engagement with the workpiece.

In addition to the main work-holding means 9, the structure of the invention includes an auxiliary work-holding means formed by a pair of auxiliary jaws 1?. which also engage the work. However, as is clearly apparent from FIGS. 1 and 2, while the main work-holding means 9, It) is in the vicinity of the working region, it is necessarily and undesirably spaced therefrom as a result of the necessity of situating the guide sleeve 3 and its holder 13 in the space between the main workholding means and the working region between the rolls 4 and 5.

The auxiliary work-holding means formed by the auxiliary jaws 12 is located between the sleeve 3 and the stop member 8 and engages the work directly in the region where working is to take place so that an exceedingly effective support is provided at the location where even a relatively short workpiece will be located. The main jaws ll) and auxiliary jaws 12 have work-engaging ends of V-shaped cross section.

A connecting means serves to connect the auxiliary workholding means to the main work-holding means. This connecting means takes the form of a pair of elongated bars ll fixed to and projecting forwardly from the main jaws lltl in the manner clearly shown in FIG. 2. It will be noted that the unit 13 which carries the guide sleeve 3 is formed with a pair of horizontal slots through which the bars 11, as indicated in FIG. 4, extend so that these bars can move laterally toward and away from the work together with the jaws 10.

While the auxiliary jaws 12 can simply be fixed to free ends of the bars 11 distant from the jaws by any suitable screws, bolts, or the like, it is preferred to provide an adjusting means at the connection between the bars 11 and the jaws 12. In the illustrated embodiment, the bars 11 are formed with longitudinally extending slots 11a along which the jaws 12 can be fixed at any selected locations simply by suitable bolt-and-nut assemblies, as shown schematically in the drawings. Thus, it is possible to regulate through this adjusting means the distance between the auxiliary work-holding means 12 and the main work-holding means 9, 10.

If desired, the adjusting means may take the form of simple grooves rather than slots 11a. Such grooves extend only partly through the bars 11 and are provided at intervals with threaded bores to receive bolts which fix the jaws 12 to the bars 11.

The length of feed of the workpiece at each feeding stroke need not correspond to the distance between the guide sleeve 3 and the head 7 of the stop member 8. While the feed stroke will usually be less than this distance, it can extend all the way up to this distance.

During the operation of the machine, while the workpiece is worked on by the wedge-rolls 4 and 5, the workpiece is rotated about its axis and directly engaged by the working rolls. This operation continues until the workpiece is finished. Then it is cut from the remainder of the rod 1 which is then advanced forwardly so that a succeeding section of the rod will have its leading end located in the recess of the head 7 of the stop member 8. The operations are then repeated with said succeeding section of the rod from which the section will be cut after it has been given the required shape by the wedgerolls.

As soon as the operations on one section of the rod are finished, the rotary movement of the wedge-rolls is terminated so that the rotary movement of the work is also terminated and a finished section is removed while a new section is supplied by the axial feeding of the rod 1 in the manner described above into the space between the rolls 4, 5. The feeding takes place by clamping the work with the retracted feed means, by displacing the main jaws and auxiliary jaws toward each other into engagement with the work, and finally by advancing all of the jaws forwardly as a unit through the feeding stroke which will locate the leading end of the workpiece in the recess of the head 7. The displacement through the guide sleeve 3 may be somewhat longer than the required length of the workpiece. With the auxiliary jaws 12 holding the work in addition to the main jaws 10, the jaws 12 contribute to the feeding of the work. After the jaws have advanced forwardly to locate the new workpiece in the region where the working takes place, the jaws are all retracted and returned to their initial position so that the work is free to rotate while being acted upon by the wedge-rolls.

However, in the case where a residual portion of the rod 1 is relatively short so that it cannot form the full length of the other sections of the rod, which form the previous workpieces, such a relatively short length 1a (see FIG. 2) cannot be moved by the jaws 10 all the way up to the stop member. It is in this situation that conventional devices require manual operations. However, with the structure of the invention, the auxiliary jaws 12 will engage and hold such relatively short residual ing means does contribute to the operations in connection with a residual relatively short workpiece 1a in that it 15 these 0 jaws 10 which cause the leading end of the next rod to press against the rear end of the residual section 1a.

When a relatively short section la moves beyond the guide sleeve 3, it is carried forward by the auxiliary jaws l2 and is, of course, also advanced forwardly by engagement with the leading end of the next rod 1. The auxiliary jaws 12 and the connecting means formed by the bars 11 participate in the operations by assuring correct introduction of the residual rod section 1a into the recess of the head 7 of the stop member 8.

Thus, it is only the last rod section which may be shorter than the other workpieces and which is guided only in the head 7 of the stop member 8 and is not guided by the sleeve 3. Of course, it may be that such a relatively short workpiece 1a will be rejected, but by including such a workpiece in the rolling operations, these operations can be carried out in a fully continuous manner without any interruptions and without any manual operations during working of the rods 1 in succession one after the other, so that this uninterrupted continuity in the automatic operations presents advantages far in excess of the relatively minor disadvantage of having rejects formed by the residual workpiece sections of relatively short length.

I claim:

1. A work-holding assembly for a cross-wedge rolling machine, wherein a workpiece is rotated while it is worked and is acted upon by wedge-rolls which control the configuration of the rotary workpiece, said work-holding assembly comprising a pair of main work-holding jaws movable toward and away from each other into engagement with the work at a location adjacent the region where the rolling of the workpiece takes place and toward and away from said region, a pair of bars respectively fixed to and extending from said main workholding jaws toward said region, a pair of auxiliary work-holding jaws fixedly carried by said bars for movement with the latter and said main work-holding jaws in the immediate vicinity of said region closer to the latter than said main workholding jaws, said auxiliary work-holding jaws engaging the work simultaneously with engagement of the work by said main work-holding jaws.

2. The combination of claim 1 and wherein said bars are formed at elongated end regions thereof distant from said main jaws with elongated cutouts extending longitudinally along said bars, respectively, and means releasably fixing said auxiliary jaws to said bars at selected locations along said cutouts thereof so that the distance between said main and auxiliary jaws can be adjusted.

3. The combination of claim 1 and wherein the workpieces are respectively in the form of elongated rods which follow one after another with each rod being cut into a predetermined length after it is worked so that a number of said lengths will be derived from each rod, and said auxiliary jaws holding an end workpiece which is too short to extend all the way up to said main jaws while the latter hold the initial end of a succeeding rod in engagement with the end workpiece of the preceding rod. 

1. A work-holding assembly for a cross-wedge rolling machine, wherein a workpiece is rotated while it is worked and is acted upon by wedge-rolls which control the configuration of the rotary workpiece, said work-holding assembly comprising a pair of main work-holding jaws movable toward and away from each other into engagement with the work at a location adjacent the region where the rolling of the workpiece takes place and toward and away from said region, a pair of bars respectively fixed to and extending from said main work-holding jaws toward said region, a pair of auxiliary work-holding jaws fixedly carried by said bars for movement with the latter and said main work-holding jaws in the immediate vicinity of said region closer to the latter than said main work-holding jaws, said auxiliary work-holding jaws engaging the work simultaneously with engagement of the work by said main work-holding jaws.
 2. The combination of claim 1 and wherein said bars are formed at elongated end regions thereof distant from said main jaws with elongated cutouts extending longitudinally along said bars, respectively, and means releasably fixing said auxiliary jaws to said bars at selected locations along said cutouts thereof so that the distance between said main and auxiliary jaws can be adjusted.
 3. The combination of claim 1 and wherein the workpieces are respectively in the form of elongated rods which follow one after another with each rod being cut into a predetermined length after it is worked so that a number of said lengths will be derived from each rod, and said auxiliary jaws holding an end workpiece which is too short to extend all the way up to said main jaws while the latter hold the initial end of a succeeding rod in engagement with the end workpiece of the preceding rod. 